This study investigates the effects of suckling on catecholamine content and turnover of discrete brain regions of mother rats. Both suckling and treatment with alpha-methyl-para-tyrosine, the catecholamine synthesis blocker, resulted in a marked increase in serum prolactin levels. Suckling caused a decrease in norepinephrne content and turnover in the anterior hypothalamic nucleus. The ventromedial nucleus responded to suckling with increases in norepinephrine and dopamine.